NASA's Climate Time Machine shows changes in key indicators

G8 countries are discussing climate change this week, and I just came across a cool site from NASA and the California Institute of Technology: a very simple, visual "Climate Time Machine" website that shows changes in some of the key indicators of climate change (average temperatures, CO2 emissions, or sea levels) over time.
(A not-so-recent visualization tool, the Sea Level Viewer, focuses on specific events over the last decade, including the Dec. 2004 Asian tsunami).